The present invention relates to a support assembly to suspend a component during the application of a coating layer to the component and a method of applying such a coating.
The exposure of components to hostile environments, such as encountered by steel parts on seafaring vessels, results in an undesirable breakdown or corrosion of the surface of such components. In order to provide protection for the exterior surface of the component, when placed in a hostile environment, a protective layer is typically applied. In certain harsh conditions such as prolonged exposure to ultraviolet light, a breakdown of the protective coating over time can occur, particularly where the protective layers are of non-uniform thickness.
The most common way to apply this layer is in the form of a sprayed paint. A disadvantage of this system is that the spray coating may be hard to apply uniformly over a large surface area of complicated geometry. A discontinuous coating layer may result from the spray process if proper coverage is not provided. These discontinuities or inclusions could result in an accelerated breakdown of the coating when the coated component is exposed to the hostile environment.
An alternate method for applying the protective layer is to dip the component in liquid paint. This method can be used for larger components with more complicated geometry, but a paint container typically has a short life span due to the drying and subsequent caking of the liquid paint on an interior surface of the container. The subsequent required maintenance and wastage of the paint material reduces the economic feasibility of this method. Another disadvantage is that for more complicated component geometry, air pockets can be trapped in various regions of the component, which affect the continuous nature of the protective coating.
One way of addressing the wastage of paint and related environmental issues is to use a fluidized bed to expose a heated part to a coating medium consisting of solid particles, which is well known in the art. One disadvantage of this system is that it is difficult to produce a coating of uniform thickness on all surfaces of a component of complicated geometry. The fluidized coating material typically collects or wells on the top surface and in pockets of the component.
It is an object of the present invention to provide a method and apparatus to obviate and mitigate some of the above mentioned disadvantages.
According to one aspect of the present invention there is provided a carriage for supporting a component to be coated including a support assembly and a plurality of coupling means to releasably secure the component to the support assembly. A plurality of motion imparting devices are mounted on the support assembly to provide predetermined movement of the component during an application of a coating layer to the component while supported by the support assembly.
In a further aspect of the invention a method is provided for applying a coating to an exterior service of a component including the steps of releasably securing the component to a support assembly and transferring a quantity of heat to the component. The component is disposed in a coating station and a plurality of motion imparting devices are activated to move the component held by the support assembly in a predetermined fashion. The exterior surface of the component is exposed to a coating medium and once the coating has been applied to the component, the component is removed from the coating station and the motion devices are deactivated. When ready, the coated component is released from the support assembly.
In a further aspect, the invention provides a method of applying at least two coatings to an exterior surface of a component which includes the steps of transferring a quantity of heat to the component and disposing the component in a coating station. Once in the coating station, the exterior surface is exposed to a primary coating medium and then subsequently exposed to a secondary coating medium within a predetermined time period. A residual component of the quantity of heat is employed to facilitate the application of the secondary coating medium to the primary coated component.
In another aspect of the invention there is provided a hook for releasably securing a component to a frame, including both a hanger end for coupling the hook to the frame and attachment end for releasably securing the hook to the component. Both of the ends are interconnected by a middle portion. The attachment end includes a notch, a plurality of edge supports located on an exterior surface of the notch and a fastener to releasably secure the component to the edge supports when the component is disposed in the notch.
In a still further embodiment of the invention there is provided a method of employing a hook for releasably securing a component to a frame including the steps of coupling a first portion of the hook to an attachment position on the frame. A cam is engaged between the frame and the first portion of the hook to secure releasably the first portion to the attachment position. The component is placed in a second portion of the hook. The second portion of the hook is releasably secured to the component by means of a fastener.